LAS VEGAS – O.J. Simpson plotted the military-style raid in which he and a gang of gun-toting men stormed into a Sin City hotel room and robbed two dealers of $80,000 in sports memorabilia, a key witness testified yesterday.

But witness Thomas Riccio, an auctioneer who brought the Juice and the dealers together, said O.J. believed he was taking back items that had been stolen from him and never mentioned that guns would be used.

After the Sept. 13 heist at the Palace Station casino hotel, he said, O.J. left him voicemail that suggests the grid great was trying to cover his tracks.

“Nobody had any guns,” Simpson allegedly claimed.

Riccio said that when he called the Juice back several hours later to say he had told cops two of Simpson’s five accomplices were packing heat, Simpson seemed depressed.

Still, he appeared confident no criminal prosecution would result.

“O.J. told me, ‘Tom, this is going to blow over in a couple of days,’ ” the auctioneer said.

Riccio testified at a preliminary hearing being held to determine whether there is enough evidence to bring Simpson, 60, and two co-defendants to trial in the stickup of memorabilia dealers Alfred Beardsley, 44, and Bruce Fromong, 53.

O.J. and his co-defendants face 12 charges, including armed robbery and kidnapping, that could put the Juice away for life.

Riccio testified that the scheme began in early August, when Beardsley contacted him, said he had access to stolen O.J. memorabilia and wanted him to find a buyer for the hot goods.

Riccio claimed he contacted O.J., and the Juice – infamously acquitted of the 1994 murders of his ex-wife and her pal – asked him to arrange a meeting with the dealers at which he would confront them and take back his belongings.

“O.J. Simpson was mainly the one plotting this out,” the auctioneer said.

On Sept. 13, Riccio rented Room 1203 at the hotel, and Beardsley and Fromong laid out their stuff on the bed.

Riccio audiotaped the confrontation, hiding the recorder in the molding of the room’s closet and hawking the tape to TMZ.com, the celebrity Web site.

Prosecutors played a six-minute, expletive-filled recording of the raid in which Simpson’s distinct baritone comes through as he repeatedly yells, “You think you can steal my s—?”

The recording ends with either Beardsley or Fromong saying, “We were just robbed at gunpoint by O.J. Simpson.”

Testifying earlier, Fromong said the raid went off in “military-invasion fashion” and one of the men pointed a semiautomatic at his face constantly.

“O.J. was screaming, ‘This is all my s—. This all belongs to me. You stole this from me. Let’s pack up. Let’s get out of here,’ ” he said.

Fromong admitted that after the heist, he called 911 and “Inside Edition,” hoping to make some money from the incident.

Fromong also said he sells Simpson autographs via the Internet, billing them as “identical to the ones O.J. stole from me.”

He waffled about whether he has been shopping a book or movie deal, saying only, “I’d like Jack Nicholson to play me if there’s a movie.”